1. Field of the Invention
The present invention relates to an apparatus.
2. Description of the Related Art
An X-ray diagnostic apparatus or an acoustic-wave acquiring apparatus has been known as an example of a measurement apparatus that acquires biological information. An acoustic-wave acquiring apparatus may be, for example, an apparatus using an ultrasonic echo or an apparatus using a photoacoustic effect. To obtain a good measurement result by such a measurement apparatus, a subject portion has to be non-movably held. If the subject portion is a part of diagnostic interest of a living body, such as a breast, a burdensome discomfort on the subject portion during measurement is desired to be reduced as much as possible to prevent a subject from feeling discomfort.
The photoacoustic effect represents a phenomenon in which when a subject portion is irradiated with pulsed light from a light source such as a laser, the subject portion absorbs optical energy, is expanded and contracted, and generates an acoustic wave (photoacoustic wave). By detecting the photoacoustic wave with use of a probe and performing signal processing and image reconstruction, an optical-property-value distribution in the subject portion is acquired and visualized.
A configuration including a bed that reduces a burdensome discomfort on a subject and a compression unit configured to provide a projected cross-sectional area of a breast sufficient for image-capturing is disclosed in Japanese Patent Laid-Open No. 7-303633 as an example of the X-ray diagnostic apparatus.
FIG. 32 is a schematic illustration showing an X-ray mammography apparatus disclosed in Japanese Patent Laid-Open No. 7-303633. This apparatus includes a bed 113 having a breast insertion hole, a compression plate 102 that compresses a breast 112, and an X-ray film table 101. The X-ray film table 101 is arranged such that the X-ray film table 101 and the compression plate 102 compress the breast 112. The X-ray film table 101 includes therein an X-ray film 105. A subject lies on the bed with her face down during image-capturing and inserts the breast 112 into the breast insertion hole. The inserted breast 112 is inserted to an area between the compression plate 102 and the X-ray film table 101. In this state, the compression plate 102 is moved to compress the breast 112. Then, an X-ray source 117 irradiates the breast 112 with an X-ray beam and an image of the breast 112 is captured.
With the configuration of Japanese Patent Laid-Open No. 7-303633, since the subject lies on the bed with her face down, the breast sags vertically downward. Hence, the projected cross-sectional area becomes large by the sagging amount. However, the bed-type compression mechanism of related art is still desired to be improved to reduce a burdensome discomfort on a subject and to increase ease of operability for an operator.